Please help!!!!!!! fan and medals!!!!!

Which relation is a function?

A.
{(1, 2); (2, 3); (3, 4); (4, 5)}

B.
{(1, 2); (3, 2); (3, 3); (4, 2)}

C.
{(1, 2); (2, 3); (3, 4); (2, 5)}

D.
{(1, 2); (1, 3); (1, 4); (1, 5)}

Question

Please help!!!!!!! fan and medals!!!!!

Which relation is a function?	
 
 A.
{(1, 2); (2, 3); (3, 4); (4, 5)}
 
 B.
{(1, 2); (3, 2); (3, 3); (4, 2)}
 
 C.
{(1, 2); (2, 3); (3, 4); (2, 5)}
 
 D.
{(1, 2); (1, 3); (1, 4); (1, 5)}

anonymous · Answer

@mathstudent55  @joshhfers

anonymous · Answer

Plot the points for each of the four answers on four separate graphs. If you can draw a vertical line though any two or more points, then it is not a function.

anonymous · Answer

i got thanks

anonymous · Answer

can you help with more

anonymous · Answer

Which is the direct linear variation equation for the relationship?

    y varies directly with x and y = 10 when x = 2.
 
 
 A.
y = 5x
 
 B.
y = x – 8
 
 C.
y = x + 8
 
 D.
y = 2x + 6

anonymous · Answer

If you look up direct variation. It states y=Kx 
Where K is a constant. 

So it looks like A is the correct answer.